But I'm a little upset they didn't bring the Greatjon back for his defiant last stand.

It seems they couldn't get him back for season 2, so I'm guessing they decided to leave him out of season 3 as well?

As for the books vs. TV discussion: I'm glad the TV series did some things differently. The main task is still to create great television, not copy-past the books. And some scenes that weren't in the books were some of the best in the show and some stuff that was abandoned for the TV show made the whole thing better. That being said, I slightly prefer the books still, because the scope is massive and because of its ambition, the books are able to do things a TV show just can't do.